Study Group on Climate and Desertification
Leader: Professor P.D. Tyson

The members of this study group are:

Dr. T.G.J. Dyer

University of the
Witwatersrand, Johannesburg, South Africa.

Dr. M.H. Glantz

National Center for
Atmospheric Research, Boulder, Colorado, USA.

Mr. A.T. Grove

University of Cambridge,
England.

Mr. D. Lee

Commonwealth Bureau of
Meteorology, Melbourne, Australia.

Professor D. Sharon

Hebrew University of
Jerusalem, Israel.

Professor H. Suzuki

University of Tokyo, Japan.

Professor P.D. Tyson

University of the
Witwatersrand, Johannesburg, South Africa.

The study group was formed in 1976 following the Ash. khabad
meeting of the Working Group. The intention was to encourage
research of various kinds relating to the general theme of
climate and Desertification (including semi-arid areas). The
meteorological and climatological framework into which the
individual studies fall has been well developed by Hare in his
background review on Climate and Desertification presented to the
United Nations Conference on Desertification in Nairobi in 1977.

The work of the study group covers a wide field of interests
including Quaternary lake-level fluctuations, coastal upwelling
and deserts, the nature of desert rainfall, synchronization of
Desertification in the world, estimation of the likelihood of
extended drought conditions in southern Africa, climate and crop
yields in semi-arid regions and monitoring rainfall deficiencies
in semi-arid regions.

The projects are as follows: Quaternary Lake Level Fluctuations: A.T. Grove In a
paper in 1976 on late Quaternary lake level fluctuations in
Africa, Street and Grove showed how much of Africa has
experienced quasi-synchronous changes in lake levels over the
last 30,000 years. This work is being extended to include global
lake levels in the Late Quaternary.

Coastal Deserts: M.H. Glantz Research is being
conducted on coastal upwelling of cold water and its influence on
coastal deserts along with desertification.

Desert Rainfall Patterns: D. Sharon Two main
investigations have been conducted. The first is concerned with
the analysis of daily rainfall in a desert area and the
determination of localized rainfall distribution or spottiness.
The second is concerned with the mesoscale structure and life
history of Negev storms.

World Patterns of Desertification: H. Suzuki The
question of synchronization of Desertification is being
considered. The extent to which the less advanced northward
extension of the Equatorial Westerlies during the 1968 to 1973
period has had world-wide repercussions is under examination.

The Likelihood of Extended Droughts in the 1980s in
Southern Africa: P.D. Tyson Maps to show the temporal and
spatial variation of rainfall over the sub-continent from the
midnineteenth century onwards have been prepared. The use of a
simple model suggests that the decade from 1983 onwards may be
one in which about seven to ten years will be drier than average.

Monitoring Rainfall Deficiencies: D. Lee In this
study the decile values of rainfall are used to provide the basis
of quasiforecasts of the probability that areas will be deficient
in rainfall for specific periods.

Crop Yields and Climate: T.G.J. Dyer Linear multiple
regression models in which combinations of mid season rainfall
and temperature are taken as predictor variables are being
formulated and used to predict end-season crop yields.
Preliminary results suggest a surprisingly high proportion of
crop-yield variance can be accounted for in this way.

The research findings of individuals in the study group have
been presented at national and international conferences, and
more than a dozen papers have been published in scientific
journals.

Study Group on the Perception of Desertification
Leader: Dr. R.L. Heathcote

The members of this study group are:

Mr. M. Butler

Adelaide College
of Advanced Education, Adelaide, South Australia.

Dr. R.L.
Heathcote

Flinders
University of South Australia, Adelaide, South Australia.

Mr. S.P.
Malhotra

Central Arid
Zone Research Institute, Jodhpur, India.

Professor T.F. Saarinen

Department of Geography,
Regional Development & Urban Planning, University of
Arizona, Tucson, USA.

Mr. M.U.A. Tennakoon

Central Bank of Sri Lanka,
Colombo, Sri Lanka.

Since much of the work of this study group has been in the
form of studies commissioned under the Natural Resources
Programme of the United Nations University, and in view of the
fact that work by other members is reported elsewhere in this
publication, the main report of the study group is included in
the United Nations University Session.

Study Group on Pastoralism and Desertification

Leader: Dr. Douglas L. Johnson

The members of this study group are:

Dr. E. Bernus

ORSTOM, Paris, France.

Dr. J.S. Birks

University of
Durham, England.

Dr. D. Campbell

University of
Nairobi, Kenya.

Dr. D. Chatty

University of Damascus,
Syria.

Professor R.J
Harrison Church

London School of
Economics, England.

Dr. W. Fricke

Heidelberg
University, Federal Republic of Germany

Dr. D.L. Johnson

Clark
University, Worcester, USA.

Dr. M.M. Khogali

University of
Khartoum, Sudan.

Dr. A. Schmueli

Tel Aviv University, Israel.

Professor B.W. Spooner

University of Pennsylvania,
Philadelphia, USA.

Dr. Johnson reported that the focus of this study group was
the response of traditional pastoral nomadic systems to change
and the implications of this response for desertification
processes. Several recent studies emphasized the ability of
traditional pastoralists to assess the carrying capacity of grass
and water at their disposal and maintain rotational grazing that
avoids environmental deterioration. Whilst some of this balance
may have been an inadvertent byproduct of pastoral nomadic
mobility, the result has been a dynamic equilibrium in most
drylands until the early twentieth century. Even in terms of
off-take rates from traditional rangelands, the record has been
one of consider able productivity.

There seems little doubt that the picture of traditional
rangeland users as rational and productive exploiters of dryland
Pesources is well-founded. However, the systems that are adaptive
under one set of socio-economic circumstances may be less
successful when conditions change. Herein lies the current focus
of the study group's investigation, which has concentrated on two
types of adaptation to change:
(1) situations where livelihoods change and population
concentration occurs, and
(2) instances where dispersed resource-use strategies are
maintained.

In the first case, pastoral nomads are increasingly responding
to change by opting out of the nomadic way of life through
sedentarization or by introducing technology in ways that
encourage local concentrations of people and flocks. In both
instances the result is excessive pressure on local environments,
leading to accelerated environmental degradation.
Characteristically, the sedentarization of nomadic groups leads
to rings of deteriorated vegetation close to the settlement, as
fuelwood collection increases and grazing pressure is locally
intensified. In other instances, introduction of concentrated
inputs such as wells results in serious local disruption when
land-use control mechanisms are not introduced simultaneously.

Two types of change affect pastoralists attempting to retain a
dispersed and mobile pattern of land use. The expansion of
dry-farm agriculturists, the conversion of dry-season pasture to
alternative land uses, and the loss of control over open
rangeland as a result of nationalization and the collapse of
traditional tribal authority, have put traditional nomadic
communities under significant stress. All of these processes have
one common feature: they remove critical resources from
traditional patterns of use and control. The amount of land
alienated to alternative use is less important than its critical
role within the traditional pastoral system. The alternative
land-use systems and development projects may be productive in at
least the short term, but the adverse social and environmental
consequences are frequently experienced in pastoral areas and
populations far removed from project boundaries.

The second type of change concentrates on using traditional
pastoral systems as the basis for new rangeland development. Few
examples of this type of concern have yet come to light, although
Syrian pastoral co-operatives offer some indication of movement
in this direction. By restoring local control over rangeland
resources and retaining modified mobility patterns, some of the
worst aspects of rangeland deterioration can be avoided and
desertification potentially reversed.

The projects are as follows:

Sedentarization and Desertification: A. Schmueli
Dr. Schmueli has studied Bedouin sedentarization in the Judaean
Desert for the last 20 years and has more recently investigated
the relationships between sedentarization and desertification in
the Sinai and Negev deserts.

Migrant Studies: J.S. Birks
Previous investigations focused on migrants to Mecca in the
Sahelian-Sudanic zone and socio-economic change among
pastoralists in Oman. His current activity is participation in
the International Migration Project which is examining labour
migration in the Persian Gulf.

Pastoral Adaption to Modern Market Systems: D. Chatty
After initial studies in the Bika Valley, Lebanon, including
transportation technology, Dr. Chatty has begun an investigation
of pastoralism in northern Syria, as well as the development of
pastoral co-operatives in the Homs-Hama area.

Resource Competition between Pastoralists and Sedentary
Farmers: D. Campbell
Dr. Campbell is presently examining competition between the Masai
and adjacent agriculturalists. Response of pastoral nomads to
drought in Maradi, Niger, from 1968 to 1973 was the focus of an
earlier study.

Pastoral Development and Drought in Northern Nigeria: W.
Fricke The final report of this investigation is about to be
published

Nomadic Pastoralism and Desertification: M.M. Khogali
and E. Bernus
Dr. Khogali is involved with the SwanseaKhartoum Research Project
which includes a pastoral component as well as a more general
examination of this theme in the Sudan.

Dr. Bernus is carrying out a study in the Tuareg area of
Niger.

Sahelian Drought Recovery: J. Sutter
Dr. Sutter has worked for three years on a pastoral development
project in Niger concentrating particularly on nomadic recovery
and also on changing terms of trade between nomadic and settled
populations.

Well Development: R.J. Harrison Church
Dr. Harrison Church is examining well development policy in West
Africa.

Study Group on Desertification in Extremely Arid
Environments

Leader: Professor Wolfgang Meckelein

The members of this study group are:

Dr. W. Achtnich

University of
Hohenheim, FederaI Republic of Germany.

Dr. J.W. Allan

University of
London, England.

Professor E.
Ehlers

University of
Marburg, Federal Republic of Germany.

Mr. O.A.H.
Ghonaim

University of
Alexandria, Egypt.

Professor I. Kobori

University of Tokyo, Japan.

Professor W.
Meckelein

University of
Stuttgart, Federal Republic of Germany.

Mr. C. Nesson

University of
Bordeaux, France.

Professor W.
Ritter

University of
Regensburg, Austria.

Dr. E. Wehmeier

University of
Stuttgart, Federal Republic of Germany.

Until recently, attention has been given almost exclusively to
desertification problems in the marginal zones of arid lands, yet
desertification has been increasingly reported from within the
deserts proper; that is from the extremely arid areas.
Deterioration or shrinkage and abandonment of the cultivated
areas have been observed in isolated small and large oases and
across oasis regions. The reasons for this are manifold and
relate to the field of physical geography as well as that of
social and economic geography.

To limit the scope of the work and objectives of the study
group, it was recommended that research should mainly concentrate
on relationships between desertification within oases and
utilization of water resources. It was considered that,
eventually, another item might be the threat caused by shifting
sand. Problems of water supply may be connected for example with
natural or artificial lowering of the groundwater table, but a
surplus of water may also have disastrous effects, causing a rise
in the groundwater table and a salinity hazard in the soils.

Such phenomena of desertification are increasing and have
contributed to a profound crisis of oases, most evident in the
deserts of North Africa and the Middle East. A detailed analysis
of causes and effects of desertification within oases is
therefore extremely important. In North Africa alone, more than
two million oasis dwellers are affected, not to speak of the 38
million Egyptians in the Nile Valley oasis and 500,000 nomads in
the Sahara desert who are also dependent on oases. These figures
underline the importance of the work in progress, which is
significant because it has a direct bearing not only on the oases
themselves but also on the utilization of resources in the
surrounding extremely arid areas. A number of case studies have
been initiated to tackle the problems mentioned above. They have
been care. fully selected according to the following criteria: -
first, all the important countries affected should be
represented; - second, the case-studies should cover as many
different aspects as possible. Both human and natural aspects of
desertification have been examined.

The projects are as follows:

ALGERIA

Desertification in the Oasis Regions of Gourara and Touat,
with Special Reference to Water Storage and to Water
Salinization, and also to Problems of Moving Sand: Wolfgang
Meckelein, in collaboration with Mrs. A. Kirchner Field studies
were carried out in the spring of 1978. Water samples were
brought to Stuttgart and analyzed there. It appears that soil
salinization is favoured not by water shortage but by bad
irrigation and drainage techniques. In the area of Gourara,
moving sands are also causing the abandonment of cultivated land.
Here the formation of dunes close to the oases seems to be
induced by man himself, in that artificial obstacles designed to
protect against shifting sand lead to the formation of larger
dunes which then endanger the oases.

Desertification In and Around the Aoulef Oases: Iwao
Kobori
The paper deals with the Tidikelt area, one of the older oasis
regions in the Western Sahara. Professor Kobori has worked there
intensively and has also published some of his results.

Desertification in the Oued Righ, Northeastern Algeria:
Claude Nesson
A publication will give examples of desertification from the
oases of Oued Righ. Areas will probably be mapped to show where
desertification has occurred already and those in which the
process is presently active. Relationships will be documented
between the phenomena of desertification and the withdrawal of
groundwater, resulting in important lowering of the groundwater
table and in harmful physical and cultural consequences. As a
contribution towards remedial programmes, this case-study will
offer a deeper insight into the dangers inherent in certain kinds
of human interference, and demonstrate the possibilities of
preventing and solving such problems in new reclamation projects.

TUNISIA

Desertification Phenomena in the Northern Oases of the
Nefzaoua Region, South Tunisia: E. Wehmeier A detailed
description and explanation of the present water situation in the
area is given. Two generations of aerial photographs (1949,
1969),, as well as two field trips (1975, 1977) and data from the
Tunisian Service de l'Eau, have helped to establish deeper
understanding of the connections between groundwater extraction
and fluctuations in the irrigated area.

LIBYA

Changes in the Oases of Southern Libya: J.A. Allan
Data have been established on relationships between the
development of water resources and the desertification processes
in the west and east of southern Libya.

EGYPT

Surplus of Water as a Main Cause of Desertification in the
Siwa Oases: O.A.H. Ghonaim
Field studies were carried out in 1974, 1976 and 1977. The
results so far show that increasing salinization is caused by
rising groundwater. The high groundwater level itself results
from a number of newly drilled wells, the water of which is only
partly used or not at all. On the other hand, the abandonment of
peripheral irrigated lands frees formerly-used spring water, and
this also contributed to the water surplus.

Desertification Phenomena in a New Desert Reclamation
Project: Wolfgang Meckelein This study aims to find out why
this new desert reclamation project, established with modern
techniques, suffers from soil salinization and moving sand. One
publication on this project appeared in 1977.

SAUDI ARABIA

Did Araoian Oases Run Dry?: W. Ritter
A number of important oases in central and eastern Saudi Arabia
owe their existence to fossil (?Pleistocene) groundwater issuing
from karst springs. Observations in Ghatghat, Aflaj, Wadi Miyah,
Yabrin and Bahrain show that during historical times there
existed either higher-located aquifers and springs, or even
higher-yielding ones than today. In some of these areas
irrigation is practiced today only by flooding, and deep wells
need to be drilled. These observations are backed by aerial
photographs which show remnants of settlements and fields, tells,
qanats, and groups of burial mounds. It remains open to debate
whether the reason for the abandonment of settlements and oases
was a gradual diminution of the fossil water resources or
socioeconomic factors.

Protective Measures Against Desertifications in Irrigation
Agriculture as Exemplified in Al-Hassa Oasis: W. Achtnich
During several years on a pilot farm in the Al-Hassa area, the
opportunity was taken to carry out studies into the prevention of
Desertification by different methods of stabilizing the soil.
This work is incomplete.

IRAN

Oases of Bam in Central Iran: E. Ehlers
This study aims to depict economic and social-geographical
structural changes due to land reform and the installation of
pumps. The problems studied include: traditional aspects of the
rural structure; effects of land reform such as decrease in
cultivated areas, out-migration and the growing of specialized
crops; and the installation of pumps and its consequences,
including lowering of the groundwater table, concentration of
irrigation agriculture in the hands of former landlords and
increased social disparities.

It is proposed to publish the various case-studies in a single
volume to be ready on the occasion of the International
Geographical Congress in Tokyo in 1980. The volume will be
furnished with an introduction on the general problems of
Desertification in extremely arid environments and contain a
concluding chapter dealing with the results and consequences of
the various research activities.

Dr. Mainguet reported that this group had been carrying out
studies of aeolian processes in the Sahel and adjacent arid
regions, and that the work had involved mapping and
systematically classifying dune types, determining the
palaeoclimatic inheritance in present landscapes, studying
external processes, principally wind action and mechanisms of
wind erosion, and formulating measures to reduce the
desertification hazards resulting from drought stress and land
use respectively. In particular, with the support of the French
Direction Générale a la Recherche Scientifique et Technique
(DGRST) over the last three years, the study group has been
engaged in a country-wide study of wind action in Niger Republic
in relation to natural and human factors, part of the findings of
which were used in the Niger Case Study for the Nairobi
Desertification Conference.

The projects are as follows:

Bibliography on Aeolian Phenomena and Measures to Combat Wind
Erosion: M. Mainguet, M. Callot and L. Canon A bibliography of
4,500 items, on aeolian phenomena in the Sahel region and
measures to prevent wind erosion, has been completed for
publication.

Mapping of Soil Degradation from LANDSAT Imagery: M. Mainguet
and L. Canon Mapping of soil degradation from LANDSAT imagery has
been carried out in collaboration with FAO and UNEP. The mapping,
at a scale of 1:5 m, has been in Chad, Central African Empire,
northern Niger, Upper Volta and eastern Mali.

Agricultural Development in the Mayahi Region, Niger: M.
Mainguet, L. Canon and M C. Chemin The above-named, with support
from staff of LPGZ, have collaborated with the Groupement
d'Etudes et de Recherches pour le Développement de l'Agronomie
Tropicale (GERDAT), the Institut de Recherches Agronomiques
Tropicales et des Cultures Vivrieres (I RAT) and the Universities
of Strasbourg and Bordeaux in a project for the development of
this agricultural region. The study has involved mapping
landforms and their dynamic status as a measure of the inherent
stability of landscapes under development.

Sand Encroachment in Oases of Southern Morocco: M. Mainguet At
the request of FAO, Dr. Mainguet took part in a project on
problems of sand encroachment in oases along the Wadis Draa and
Ziz. This work is described in a contributed paper under Physical
Aspects of Desertification in this publication.

Field Studies of Aeolian Processes: M. Mainguet, L. Canon,
A.M. Chapelle and M.C. Chemin Wind and rainfall records (1965 to
1975) of principal stations in Niger have been analysed. In the
Niger Sahara, a quantitive analysis of sand found at the
extremities of tracts affected by dominant wind currents has been
completed by Dr. Mainguet. An investigation into the dynamics of
ergs and dunes has been conducted on the Erg of FachiBilma
(Chad-Niger) by Dr. Mainguet and Y. Callot. With L. Canon, Dr.
Mainguet has produced a map of the extent of reactivation of sand
mantles in relation to external dynamics and land development in
the region of Eghazer and Azaouak, Niger, which was used in the
Niger Case Study for the UN Desertification Conference. The
installation of sand traps is planned in Upper Volta, to further
the study of the aeolian processes involved in desertification.

Long-distance Wind Transport of Sand as Detected by Satellite
Imagery: M. Mainguet, L. Canon, and M.C. Chemin Satellite imagery
has been used to identify vast trans-Saharan arcs within which
wind action is concentrated, and along which sectors of
predominant erosion, transport and deposition can be
distinguished.